中温烧结BaTiO_3基多相铁电瓷料X7R特性

采用铋钛低熔物降低ＢａＴｉＯ３基资料的烧结温度。当加入量约０．０５ｍｏｌ时，可实现中温烧结，此过程存在过渡液相烧结。改性添加物Ｌａ２Ｏ３、Ｎｂ２Ｏ５等在固－液烧结过程中溶－析及Ａ、Ｂ位缺位补偿因溶，使主晶相ＢａＴｉＯ３晶粒形成“核－壳”结构。从ε－Ｔ特性和微观结构分析，探讨了不均匀分布的ＢａＴｉＯ３基多相铁电瓷料具有Ｘ７Ｒ特性的机制。     

2F4特性瓷料中SrTiO3的改性作用

研究了２Ｆ４特性瓷料中加入少量ＳｒＴｉＯ３及ＳｒＴｉＯ３的加入方式对材料介电性能和窑业性能的影响．试验表明，在以ＢａＴｉＯ３－ＣａＳｎＯ３为主的２Ｆ４特性瓷料中加入少量的ＳｒＴｉＯ３有明显的改性作用．ＳｒＴｉＯ３的加入使瓷料居里峰展宽、负温度特性变好、介质损耗降低，耐电强度提高．ＳｒＴｉＯ３加入方式明显影响烧结性能．先将ＢａＣＯ３、Ｓｒ－ＣＯ３、ＴｉＯ２共同合成（Ｂａ１－ＸＳｒＸ）ＴｉＯ３固溶体再进行配料烧结的比用ＢａＴｉＯ３、ＳｒＴｉＯ３进行配料烧结的有较宽的烧成范围和较好的耐潮性．     

BaO—PbO—Bi_2O_3－Nd_2O_3－TiO_2系陶瓷的物相和电性能

研究ＢａＯ－ＰｂＯ－Ｂｉ２Ｏ３－Ｎｄ２Ｏ３－ＴｉＯ２五元系统在８００～１２００℃烧结中物相变化和电性能．ＸＲＤ测试数据：１０００℃时ＢａＴｉＯ３消失，主晶相为ＢａＴｉ４Ｏ９、Ｂｉ４Ｔｉ３Ｏ１２和Ｎｄ２Ｔｉ２Ｏ７，ＢａＮｄ２Ｔｉ５Ｏ１４开始出现，１１００℃到１１５０℃，Ｂｉ４Ｔｉ３Ｏ１２在ＸＲＤ图上消失，ＢａＴｉ４Ｏ９和Ｎｄ２Ｔｉ２Ｏ７含量逐渐减少，ＢａＮｄ２ＴｉＯ１４逐渐增加；１２００℃时，ＸＲＤ图谱全部为ＢａＮｄ２Ｔｉ５Ｏ１４，证明该系统的主晶相ＢａＮｄ２Ｔｉ５Ｏ１４是由Ｎｄ２Ｏ３、ＴｉＯ２对具有微波特性的ＢａＴｉ４Ｏ９改性而得：铅含量增加，主晶相的ａ、ｂ二晶轴缩短．调整各组分及玻璃的含量，获得ε＝９０±５、损耗ｔｇδ≤３×１０－４、绝缘电阻ρｖ≥１０１２Ωｃｍ、电容量温度系数αｃ＝０±１５×１０－６／℃、中温（１１５０℃）烧结的ＮＰＯＭＬＣ瓷料．     

线性高频电容器瓷料的研究

研制一种以ＳｒＴｉＯ３－Ｂｉ２Ｏ３·ｎＴｉＯ２－ＣａＴｉＯ３为主晶相的Ｖ组线性电容器瓷料．以三、五族氧化物为改性剂，使容量温度特性线性化；加ＰｂＴｉＯ３，使介电常数提高．其介电常数ε＞３１０，电容温度系数αｃ＝（－１５００±２５０）×１０－６／℃，其余各项电气、物理、机械性能均符合国际ＧＢ５５９６－８５．     

BaTiO3基抗还原陶瓷材料的研究

研究了ＢａＴｉＯ３基抗还原陶瓷材料的结构和介电性质,讨论了ＺｒＯ２、ＭｎＯ和ＢＴ系中摩尔比ｍ对瓷料抗还原性能和介电性能的影响。通过调整上述参量加入适量的添加剂,获得了在氮气中烧成并符合Ｆ组性能要求的ＢａＴｉＯ３基抗还原陶瓷材料。     

BMN,BZN掺杂工业用BaTiO3基陶瓷的介电损耗

采用固相反应合成了Ｂａ（Ｍｇ１／３Ｎｂ２／３）Ｏ３（ＢＭＮ），Ｂａ（Ｚｎ１／３Ｎｂ２／３）Ｏ３（ＢＺＮ）复合钙钛矿型粉末，并用它来改善工业ＢａＴｉＯ３瓷的介电损耗特性，实验结果表明１３００－１４００℃烧结后，可获得至密度为９０％左右的瓷体。同时经频谱阻抗分析实验，表明这类材料随频率从１ＫＨｚ增加到１０００ｋＨｚ介电损耗显著降低，品质因数大幅度改善。     

低温烧结PZT压电陶瓷的研究

对ＰＺＴ压电陶瓷的低温烧结进行了研究。实验发现，在ＰＺＴ陶瓷中添加少量低 熔玻璃（ｘＢ２Ｏ３－чＢｉ２Ｏ３－ｚＣｄＯ）可使烧结温度从１２５０℃降低至９６０℃。其性能参数： Ｋｐ≥０．５２～０．５６，Ｑｍ≥１０００，ε３３Ｔ／ε０＝８００～１２００， ｔｇδ≤５×１０－３．借助于扫描电镜 （ＳＥＭ）、电子探针微区分析（ＥＰＭＡ）、Ｘ光光电子能谱分析（ＸＰＳ）和体积烧缩速率的 测量，对陶瓷显微结构、烧结机理和添加剂的作用进行了讨论，所研制的低温烧结瓷料 巳用于制备独石压电陶瓷变压器，其空载交流升压比可高达 ９ ０００以上。     

A RESEARCH ON THE MEDIUM TEMPERATURE SINTERED BaTiO_3-BASE CERAMIC MATERIAL FOR MLC WITH X7R BEHAVIOR

采用加入Ｂｉ２Ｏ３＿ＰｂＯ＿ＺｎＯ玻璃及Ｂｉ、Ｃｏ、Ｎｂ掺杂的方法，使ＢａＴｉＯ３基铁电瓷料中温烧结（１０８０～１１４０℃）。在实验结果的基础上，探讨Ｘ７Ｒ铁电瓷料中的第二相和晶粒尺寸对ＭＬＣ的ε＿ｔ性能的影响，并研究其烧结机制。     

复合掺杂对BaTiO3瓷介电常数温度特性的影响

研究了Ｄｙ－Ｎｂ、Ｃｅ－Ｎｂ氧化物复合掺杂对ＢａＴｉＯ３瓷温度特性的影响。结果表明，能使ＢａＴｉＯ３瓷的介电常数－温度关系曲线变得相当平缓。对造成此结果的原因，进行了理论分析和讨论。     

中温烧结（BaLa）（TiNb）O_3基铁电材料的研究

本文简要探讨高价阳离子Ａ、Ｂ双位取代ＢａＴｉＯ３系固溶体的中温烧结机制，以及其所形成的复合缺陷机构对介电特性的影响，并从实用出发，研制开发了（ＢａＬａ）（ＴｉＮｂ）Ｏ３系ＸＬ１０３片式多层瓷介电容器（ＭＬＣ）资料，其主要的特征参数为：ε（２０℃，１ｋＨｚ）≈１００００；在－２５～＋８５℃范围内　Ｔｓ＝（１１１０±２０）℃     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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